Process of making helical rolls.



G. S. LOGKWOOD.

PROCESS OF MAKING HELIGAL ROLLS.

APPLICATION FILED SEPT. 25, 1912.

1,064,975. Patented June 17, 1913.

@W Wvwwcm A CHM/WV as I CHARLES s. :tocxwoo'n, or NEWARK, nnvrl .iEnsnY, ASSIGNOR r0 HYAT']? Rotten BEARING COMPANY,YJFI3IARRISON, NEW JERSEY, A CORPORATION on NEW .TERsEY.

recesses or Max ne semen ROLLS.

specification of Letters'ratent. Application filed September 25, 1912. Serial No. 722,186.

rate-men June 1?,1'913.

To all whom it may concern:

Be it known th'at L'Cimnnns S. LOGKWOOD, a citizen of the United States, residing at 289 Market street, fewark, county of Essex, and State-of New Jersey, have invented certain new and useful Improvements in Processes of Making Helical Rolls, fully described and represented in the following specification and the accompanying draw ings, forming a part of the same.

The object'of'the present invention is to obviate the objections to the use of rectangu-' lar or flat strips, in the formation of rolls by Winding'flat strips upon a mandrel, and such object is attained by making a strip of arc sheped section and applying the concave side of such st-rip to the mandrel in the winding operation. 7

The objections to the use of a Hat strip Will'b fully described herein, and they have become especially serious in the increasing demand for strong spirally .wound rolls to resist heavy loads, thus necessitating the use of strips much thicker than those heretofore employed. Strips exceeding in thickness one-third the bore of the roll and often equaling one-half of such bore are now employed in the winding of, helical rolls to sustain heavy loads, such as are imposed upon them in automobile bearings and under similar conditions of comparatively recent origin. It is common to use strips that are Wide in proportion to the diameter of the roll, so as to increase the bearing snriaceot each coil, and such a strip therefore makes a considerable angle to the axis of the roll.

lVhatever. the thickness of the strip its Winding upon the mandrel at a considerable angle tends to compressthe inner side of the strip and stretch its outer side, and to thus give the strip a. shallow trough-shaped cross-section which pl'fitlllvtn' an elevation at each side of the strips, with resulting ridges upon the roll at the joints of the coils. W'ith soft steel of ductile character, such ridges can be easily cll'aced by rolls while the coils are winding upon the mandrel, but at the present time strips of high-carbon steel are employed so that the rolls canbe hardened and ground to avoid wear.

In winding a relatively thin' strip upon a mandrel it is comparatively easy, by tension upon the strip and pressure by winding rolls, to conform the strip :u-curati :ly to the mandrel and thus make the QXlGllol' of the rolls cylindrical; but when a strip'of relatively great thickness is nadet of highcarbon steel and wound upon "it "relatively small mandrel, the difiiultyof conforming the strip to the mandrel and producing coils with a cylindrical exterior is enormously increased. This difliculty is practically over come in the present invention by anticipat= mg the change of form which the winding ofthe strip produces, and tormingthe strip primarily of such a shape as to counteract or neutralize the said change. 'I' have found thatthe required compensation can be pro;

duced by using a strip of arc-'shaped'crosssection and applying the concave side "of the stripto the mandrel during the wind mg operation, and propontioning: the curves upon the inner and outer sides of t-he strip to equal the change of form which 'is produced by winding upon a mandrel. of a oer tain size.

The'invention will be understood by reference to the annexed drawing,- in which- Figure 1 IS a perspective view of a strip having the arc-shaped section; Fi 2 shows rollers uponthe strip during'fthei winding operation; Fig; :6 is an *elevation'ofthe 'm'an-- drel with a section of ,fourcoi'ls' Wound thereon having the required arc-shaped section; and Fig. 7 is anelcvation of the mandrelv with a section of three coils wound from a rectangular strip.

Figs. 4t and 5 show amandrel a having a strip 6 applied thereto and wound into coils b which are bent and compressed by bend: ingq-ollcrs 0 during the winding operation. A gage (Z is, in practice, held ri 'idly at the rear side of the coils Z) so that the strip can be held back during the winding operation without bonding the mandrel, and thus pro duce a tension of any desired degree upon the coils. the bendingmollers c serve to bend highly resistant strip around the small mandrel shown.

Fl 7 exhibits the change of cross-section \\'lllC) occurs when .a thick rectangular strip is wound upon relatively small man- Such tension and the pressure of I drel, the angle of coils and the compressing and expanding of the strip upon itsfinner and 'outer sides tending to throw vthe elevation of'the outer'ed'ges'of the strip the edges upwardly and to narrow the outer side of the strip. Such a deformation- -.of the strip produces ridges at the joints of the coils, which cannot be satisfactorily rolled down to secure an even cylindrical surface if thick strips of high-carbon steel be used; ,but the present invention obviates the production "of such ridges by forming the'strip, in advance, of arc-shaped section and placin it, as shown in Fig. 2, with its concave si e upon the mandrel when .Winding it thereon. Such provision anticipates during the winding operation, and when the curvature is properl proportioned to the diameter of the man rel and the width and thickness of the strip, which is readily determined by ex eriment, the outer edges become elevated uring thewinding operation into line with the middle portion of thestrip, so that it fits the cylindrical surface of the mandrel, as shown in the coils-b .of Fig. 6, and presents a truly cylindrical Y exterior with far less pressure,by the bending-rollers than would be required to prevent the deformation of the coils 6 shown in Fig. 7. Y

The strip with convex outer surface B and .concave inner surface B is readily parallel edges B as shown in Fig. 2,

side of the strip would tend-to narrow the outer side and; form wedge-shaped grooves or channels between the coils as shown in Fig. 7; but without forming ridges upon the exterior of the roll as shown in that figure. Y i

The grooves are not undesirable, as they serve to hold and distribute upon the axle and easing the lubricant which is sup lied to therolls in a roller-bearing. If, 10wever, it desired to wind the rolls with" not only a cylindrical exterior but without the channels, the strip may be made as shown in Fig. 2 with flarin'g sides B proportioned shapedby suitable rolls, and when made- .wit

the extension ofthe metal upon the outerwitnesses.

to compensate for the contraction in the outer, width of the stripwhen wound into a roll of given size.

By 'my invention, spirally wound rolls the inner-side of the stri into-conformity with the mandrel as it. is entthereon.

2. The process of forming helical rolls, which consists in applying a strip of arcshaped sect-ion progressively to a mandrel with its concave side restin thereon, winding the strip upon the man rel and pressing and drawingthe strip into conformity'with the cylindrical surface of the mandrel.

3. The process of forming cylindrical helical rolls, which consists 'in winding a 4 strip of arc-shaped section upon a cylindrical mandrel with its concave side next thm outer corners of the strip even with the middle portion when wound. y

4. The process of making helical rolls which consists in forminga stri of arcshaped section with flaring edges applying the strip to amandrel with its concave 'side resting thereon, and winding the strip liipon the mandrel and pressing and drawing the strip into conformity'with the cylindrical surface of the mandrel.

In testimony whereof I have hereunto set my hand in the presence of two subscribing CHARLES S. LOCKWOQD.

Witnesses:

G. C. STUL'rs, H. E. SAUL.

v mandrel, and the convexity of the strip being proportioned to automatically bring the 

